Servicer's Note - Maytag Built-in Refrigeration Manual

There are three heaters wired in parallel for the defrost system. The glass defrost heaters
are attached to the evaporator coil, the foil drip pan heater is under the drip tray and the
tube heater is around the drain tube to prevent freeze-ups leading out of the evaporator
section. Defrost termination is provided by the evaporator thermistor readings. There is a
mechanical defrost thermostat wired is series with the heaters to act as a safety thermostat
should the Main Control board fail to open the defrost circuit.
The defrost water is routed from the evaporator area to the machine compartment through
the divider wall. The water flows into an evaporation tray with wicking pads to accelerate
evaporation. These pads are located in the airpath after the condenser and the compressor
so that warmed air can aid in evaporation.

Servicer's Note

Defrost Heater Locations
The defrost system can be energized through the Service Tests mode. Service Test 11
will energize the defrost heaters so long as the defrost terminator is closed. The defrost
system will draw approximately 3 amps.
While in Service Test 11 the display will show the evaporator temperature. A rising
evaporator temperature will confirm that the defrost heater is energized without the need
to access the evaporator.
The defrost heaters are accessed in the same manner as the evaporator coil.
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